RFID Tag Counting Ending Method Using Feedback Loop
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Solution Overview
Problem
In RFID systems, existing anti-collision methods like time slot ALOHA and binary tree algorithms fail to ensure all tags are counted correctly due to channel competition and instability in the electromagnetic field, leading to tag omission during the counting process.
Innovation Solution
A method where tags set their counters to 0 and respond to the reader-writer if not successfully counted, and the reader-writer continues counting until no response is received, using a register threshold to determine completion, ensuring all tags notify the reader-writer of incomplete counting.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If binary tree algorithm is used for anti-collision, then collision is reduced, but tag omission occurs due to channel competition and electromagnetic field instability
Solution Approach 1:
The patent introduces a feedback mechanism where tags send response signals to the reader-writer during the counting process. The reader-writer uses these response signals to determine whether a tag has been successfully counted, and continues the counting process until no more response signals are received. This feedback loop ensures that all tags are accounted for and prevents tag omission while maintaining the binary tree algorithm's anti-collision performance.
2Measurement precision
If counting process continues until all tags respond, then tag omission is reduced, but counting time increases
Solution Approach 1:
The patent applies preliminary action by having tags set their counter values to 0 before the counting process begins. This pre-initialization ensures that tags are ready to respond immediately when called, and the reader-writer can efficiently determine when counting is complete by checking for response signals. This preliminary setup reduces the overall counting time while maintaining accuracy.
3Device complexity
If register threshold is used to determine counting completion, then counting ending is simplified, but tag omission may occur if threshold is not properly set
Solution Approach 1:
The patent implements self-service by having tags automatically set their counter values to 0 and prepare to respond when needed. The reader-writer simply needs to check for response signals and update the register accordingly. This self-service approach simplifies the control logic for the reader-writer while ensuring accurate tag counting, as the tags themselves manage their counting state without requiring complex external control.
Data Source
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AI summary
The present invention provides a radio frequency identification (RFID) system and a tag counting ending method for anti-collision thereof. The RFID system comprises a reader-writer and tags. The tag counting ending method comprises: in the counting process, when the reader-writer does not receive a response signal from a tag and the value of a register is not greater than a pre-determined counting ending register threshold value, the reader-writer transmits a Finish command to each of the tags and waits for responses; after receiving the Finish command, the tag determines whether the tag itself is counted successfully, if so, makes no response; if not, sets the counter of tag itself as 0 and transmits a response signal to the reader-writer; if the reader-writer receives the response signal, then determines that counting is not finished and continues to count the tag which makes response; if the reader-writer does not receive the response signal, then determines that counting is finished.